1. Field of Invention
This invention relates to the field of chemistry and more specifically to testing for RDX with a ligand-binding assay.
2. Description of Related Art
Since World War II, an explosive known as C-4 has been widely used for military and civilian operations, such as excavation and demolition. C-4 contains an environmental contaminant known 1,3,5-Trinitroperhydro-1,3,5-triazine (RDX). RDX can migrate through soil and contaminate underlying groundwater aquifers and may be harmful to humans at relatively low levels. The EPA has established a lifetime health advisory guidance level of 0.002 milligrams per liter (mg/L) for RDX in drinking water. The EPA has identified more than thirty RDX contaminated sites on its list of national clean-up priorities.
There are several problems known in the art for testing for the presence of RDX to make determinations relevant to a potential need for remediation. RDX concentrations are discrete particles that are irregularly dispersed throughout the soil. The concentration of samples from adjacent areas may vary considerably. Current RDX testing methods are intended to provide data about precise quantities of RDX using highly sensitive, off-site instrumentation to separately test each sample. This type of high-sensitivity off-site testing is not appropriate for wide scale EPA and private environmental remediation projects, and often does not yield the necessary type of data for evaluating dispersal patterns over potentially contaminated site.
For purposes of planning and remediation, it is important to be able to test many samples to determine the presence or absence of contaminants over a dispersed area and patterns of dispersal. Current high-sensitivity testing methods performed off-site are costly and prone to delay because they cannot be performed in situ.